1. Field of the Invention
The present invention relates to a floating support structure, and more specifically to a floating support structure, which can restrain conduction of vibrations from a wiper frame of a wiper apparatus to a vehicle body.
2. Description of Related Art
A wiper apparatus is generally arranged at a lower end of a windshield of a vehicle. Some previously proposed wiper apparatuses have a wiper frame, which is installed to a vehicle body. A wiper motor and a wiper link mechanism are connected to the wiper frame. The wiper link mechanism coverts rotation of the wiper motor to rotational reciprocating movement of a pivot shaft. A wiper arm is secured to the pivot shaft, and a wiper blade is connected to a distal end of the wiper arm. During operation of the wiper apparatus, the rotation of the wiper motor is converted to reciprocatory pushing and pulling movements of the wiper link mechanism. The reciprocatory pushing and pulling movements of the wiper link mechanism generate vibrations in the wiper link mechanism and are conducted to the wiper frame. Also, vibrations are generated in the wiper motor and are also conducted to the wiper frame. Thus, in a process of installing the wiper frame to the vehicle body, a floating support structure (vibration damping rubber) is provided between the wiper frame and the vehicle body to restrain conduction of the vibrations from the wiper frame to the vehicle body.
FIG. 11 is a partial schematic cross-sectional view, showing a previously proposed floating support structure. A pivot holder 51 is integrally connected to a wiper frame (not shown) and rotatably supports a pivot shaft (not shown). The pivot holder 51 has a mounting portion 52. A mounting hole 52a penetrates through the mounting portion 52, and a vibration damping rubber 53 is inserted into the mounting hole 52a of the mounting portion 52. The vibration damping rubber 53 includes a receiving through hole 54, which penetrates through the vibration damping rubber 53. A collar 55 is inserted into the receiving through hole 54. The collar 55 includes a cylindrical body 56 and a flange 57. The flange 57 extends radially outwardly from one end (lower end in FIG. 11) of the cylindrical body 56. A through hole 56a axially penetrates through the cylindrical body 56 and is formed as a threaded hole. A fastening hole 58a penetrates through a vehicle body 58.
A bolt 59 is inserted through the fastening hole 58a of the vehicle body 58 and is threaded into the threaded hole 56a of the collar 55, which is, in turn, inserted into the receiving through hole 54 of the vibration damping rubber 53. Thus, the mounting portion 52 is floatingly supported by the vehicle body 58 through the vibration damping rubber 53. At this stage, the other end 56b (upper end in FIG. 11) of the cylindrical body 56 of the collar 55 abuts against a circumferential edge of the fastening hole 58a of the vehicle body 58. In this way, excessive compression of the vibration damping rubber 53 between the vehicle body 58 and the flange 57 of the collar 55 upon tightening of the bolt 59 is restrained by the other end 56b of the collar 55. Thus, a reduction in vibration damping performance of the vibration damping rubber 53 is advantageously restrained. As shown in FIG. 12, the collar 55 can be insert molded into the vibration damping rubber 53.
In the above state where the other end 56b of the cylindrical body 56 abuts against the circumferential edge of the fastening hole 58a, when the bolt 59 is further threadably tightened, an excessive force can be applied from the other end 56b of the cylindrical body 56 due to the fact that an end surface area of the other end 56b of the cylindrical body 56 is relatively small. This excessive force applied from the other end 56b of the cylindrical body 56 can generate a crack, such as a crack K shown in FIG. 13A, around the circumferential edge of the fastening hole 58a. Furthermore, the relatively small surface area of the other end 56b of the cylindrical body 56 can also cause the other end 56b of the cylindrical body 56 to be inserted into the fastening hole 58a when the bolt 59 is further threadably tightened, as shown in FIG. 13B.
To address the above disadvantage, it is conceivable to enlarge the fastening hole 58a, so that the other end 56b of the cylindrical body 56 is inserted through the fastening hole 58a and directly abuts against the bolt 59. However, when the fastening hole 58a is enlarged to have a clearance between the circumferential edge of the fastening hole 58a and the other end 56b of the cylindrical body 56, a mounting position of the wiper frame relative to the vehicle body 58 can be improperly shifted.
Furthermore, it is also conceivable to provide two collars 60, 61, which are inserted into the vibration damping rubber 53, as shown in FIG. 14. The collar 61 has a relatively large flange 61a, which abuts against the circumferential edge of the fastening hole 58a of the vehicle body 58. However, the provision of the two collars 60, 61 increases the number of the components and the number of the manufacturing steps, causing an increase in the manufacturing costs.
Furthermore, when the bolt 59 is tightened or loosened relative to the threaded hole 56a of the cylindrical body 56 of the collar 55, it could happen that the collar 55 rotates together with the bolt 59 relative to the vibration damping rubber 53, so that the bolt 59 cannot be further tightened or further loosened. This is likely to happen particularly when the bolt 59 is rusted.
The present invention addresses the above disadvantages. Thus, it is an objective of the present invention to provide a floating support structure that can securely mount a mountable member to a mount member without causing a substantial increase in a manufacturing cost of the floating support structure.
To achieve the objective of the present invention, there is provided a floating support structure for floatingly supporting a mountable member relative to a mount member. The floating support structure includes a mount assembly. The mount assembly has a collar and a vibration damping member. The collar includes a hollow cylindrical body, a larger diameter flange and a stopper. The hollow cylindrical body has female threads formed along an inner circumferential surface of the cylindrical body. The female threads of the cylindrical body are threadably engageable with a screw member, which is inserted through a fastening hole of the mount member, to secure the collar to the mount member. The larger diameter flange is provided at one end of the cylindrical body located apart from the mount member. The stopper protrudes from the larger diameter flange generally in an axial direction of the cylindrical body on a cylindrical body side of the larger diameter flange and is located between opposed side walls of a mouth of a recessed opening that is recessed in a mounting portion of the mountable member in a direction perpendicular to the axial direction of the cylindrical body of the collar. The vibration damping member includes a tubular body, a first flange and a second flange. The tubular body extends in the axial direction of the cylindrical body of the collar and has a receiving through hole. The receiving through hole axially penetrates through the tubular body and receives the cylindrical body of the collar. The tubular body is received in the recessed opening of the mounting portion of the mountable member. The first flange is provided at one end of the tubular body located adjacent to the mount member. The second flange is provided at the other end of the tubular body located apart from the mount member. The vibration damping member is clamped between the larger diameter flange of the collar and the mount member when the screw member is threadably engaged with the female threads of the cylindrical body, so that the mountable member is floatingly supported relative to the mount member.
To achieve the objective of the present invention, there is alternately provided a floating support structure for floatingly supporting a mountable member relative to a mount member. The floating support structure includes a mount assembly. The mount assembly has a collar and a vibration damping member. The collar includes a hollow cylindrical body, a larger diameter flange and a smaller diameter flange. The hollow cylindrical body has female threads formed along an inner circumferential surface of the cylindrical body. The female threads of the cylindrical body are threadably engageable with a screw member, which is inserted through a fastening hole of the mount member, to secure the collar to the mount member. The larger diameter flange is provided at one end of the cylindrical body located apart from the mount member. The smaller diameter flange is provided at the other end of the cylindrical body located adjacent to the mount member. The smaller diameter flange is urged against a circumferential edge of the fastening hole of the mount member when the screw member is threadably engaged with the female threads of the cylindrical body. The vibration damping member includes a tubular body, a first flange and a second flange. The tubular body extends in the axial direction of the cylindrical body of the collar and has a receiving through hole. The receiving through hole axially penetrates through the tubular body and receives the cylindrical body of the collar in such a manner that the other end of the cylindrical body of the collar is inserted through the receiving through hole of the tubular body of the vibration damping member. The tubular body is received in a recessed opening that is recessed in a mounting portion of the mountable member in a direction perpendicular to the axial direction of the cylindrical body of the collar. The first flange is provided at one end of the tubular body located adjacent to the mount member. The second flange is provided at the other end of the tubular body located apart from the mount member. The vibration damping member is clamped between the larger diameter flange of the collar and the mount member when the screw member is threadably engaged with the female threads of the cylindrical body, so that the mountable member is floatingly supported relative to the mount member.